Purpose: To compare the incidence of anterior subcapsular lens opacities, clinically significant cataracts, secondary lens-related surgical reinterventions, and vaulting characteristics of the now discontinued V3 and currently used V4 Staar Surgical Implantable Contact Lens (ICL) phakic intraocular lens designs.
Methods: In this non-randomized prospective clinical trial, 87 eyes were implanted with the V3 and 523 eyes with the V4 ICL as part of the U.S. FDA clinical trial for myopia. LOCS III assessment of lens opacities, clinically significant cataract, ICL vaulting (clearance between ICL and crystalline lens), and secondary ICL-related surgeries were the main outcome measures. Mean follow-up in the V3 series was 30.7 +/- 10.0 months (range 10.8 to 49.3 mo) and in the V4 series, 17.3 +/- 6.9 months (range 0.25 to 38.5 mo).
Results: Incidence of anterior subcapsular opacities was significantly higher with the V3 vs. V4 ICL (12.6% vs. 2.9%, P<.001). The difference was largely due to the higher rate of late-appearing opacities (> or = 1 year after surgery; 9.2% vs. 0.6%, P<.001). The V3 group had a greater proportion of eyes with poor vault (23.6% vs. 4.3%, P<.001) and the presence of poor vault was highly associated with the development of late anterior subcapsular opacities (P<.001). Clinically significant cataract was more frequent in the V3 vs. V4 ICL (9.2% vs. 0.8%, P<.001), as was cataract extraction (6.9% vs. 0.2%, P<.001), and need for ICL replacement (5.7% vs. 1.1%, P<.001). Differences in opacity rate between the V3 and V4 designs were not due to differences in postoperative follow-up.
Conclusion: Implantation of the currently used V4 Staar Surgical model ICL resulted in significantly less anterior subcapsular opacities, clinically significant cataracts, and secondary ICL-related surgery.